Since March, Japan had been asking airlines to deny boarding of passengers without negative coronavirus testing results taken within 72 hours of departure. Until Sunday, the country's quarantine authorities, however, still allowed those who had come to Japan with insufficient certificates to stay at a designated facility and retake a coronavirus test after three days. But the authorities said such alternative treatment will no longer be available, as the country reels from surging infections. To enter Japan, a passenger needs to obtain a certificate that proves negative results for the virus based on nasopharyngeal or saliva samples, which need to be taken within 72 hours before departure. Japan does not approve antigen or antibody tests as certificates for entering the country.